In order to increase the efficiency of underground mining operations, mining professionals are increasingly utilizing continuous loading and conveying systems. Less labor intensive, and considerably safer than current batch systems, continuous systems provide faster and larger throughput capacities at lower costs.
One particular continuous system that has received a favorable reception in the mining industry is assignee's OSCILOADER.RTM. continuous loader. The loader conveys large quantities of material away from a muck pile at a high rate. See Canadian Patents 1,191,487 and 1,191,488 and U.S. Pat. Nos. 4,648,776 and 4,749,326.
In brief, the referenced loader utilizes a chain flight conveyor moving above a stationary conveyor bed. The conveyor is used to load and convey abrasive, fragmented ore away from a muck pile and up an incline as the conveyor is advanced into the pile. The conveyor system has the advantage of providing the desirably aggressive and steep angle characteristics of the chain and flight conveyor. The difficulty occurs in that certain moving ore and muck are very erosive. In relatively short order, the friction and high rates of wear caused by the juxtaposition of the moving flights and stationary bed necessitate bed replacement. Chain flights are generally preferred to transport the ore since they are resistant to the damage caused by the moving rock.
Various attempts have been considered to reduce the friction and high wear rates experienced with conventional chain flight conveyors. One arrangement has made use of low friction, high wear resistant stationary plates placed between the moving chain/load mass and the underlying stationary conveyor structure. This arrangement has met with only partial success since the remaining friction level is still too high.
Conventional rubber belt conveyors lack the aggressive loading and steep operating angle characteristics provided by the chain flight conveyor that are required for excavation loading applications.